The sysuser_sysusergroup and sysuser tables do not even exist on my SQL Server 2000 installation – are they standard? I'm sure that I could help out if I understood the...
In the interests of referential integrity, you'll probably need two delete statements. The first will delete the relevant invoice lines and the second their corresponding header records.
You need to use aliases ... effectively creating two instances of the TeamList table and then using them as if you had two separate (but identical) tables ...
If the answer to Jeff's question is that column 1 is unique and ascending (as it appears from your example), I still can't think of a quick way of doing this ......